E-Jurnal Universitas Tunas Husada Tasikmalaya
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Practical approaches to labelling terminal alkynes with deuterium
No full textBase catalysed exchange with sodium hydroxide, calcium oxide or N,N,N,N-tetramethylguanidine in deuterium oxide is a viable procedure for the preparation of terminally deuterated alkynes for those alkynes stable to strong base. The use of silver perchlorate as a catalyst is an alternative practical option when labelling alkynes which are sensitive to base or contain functionalities which would lead to labelling elsewhere in the molecule. Labelling with this catalyst takes place smoothly at ambient temperature in a mixture of N,N-dimethylformamide and deuterium oxide
Deep Reinforcement Learning-based Power Allocation in Uplink Cell-Free Massive MIMO
No full textA cell-free massive multiple-input multiple-output (MIMO) uplink is investigated in this paper. We address a power allocation design problem that considers two conflicting metrics, namely the sum rate and fairness. Different weights are allocated to the sum rate and fairness of the system, based on the requirements of the mobile operator. The knowledge of the channel statistics is exploited to optimize power allocation. We propose to employ large scale-fading (LSF) coefficients as the input of a twin delayed deep deterministic policy gradient (TD3). This enables us to solve the non-convex sum rate fairness trade-off optimization problem efficiently. Then, we exploit a use-and-then-forget (UatF) technique, which provides a closed-form expression for the achievable rate. The sum rate fairness trade-off optimization problem is subsequently solved through a sequential convex approximation (SCA) technique. Numerical results demonstrate that the proposed algorithms outperform conventional power control algorithms in terms of both the sum rate and minimum user rate. Furthermore, the TD3-based approach can increase the median of sum rate by 16%-46% and the median of minimum user rate by 11%-60% compared to the proposed SCA-based technique. Finally, we investigate the complexity and convergence of the proposed scheme. cc Index terms— Cell-free massive MIMO, deep reinforcement learning, fairness, power control, sequential convex approximation
The artist and the photograph: A semiotic analysis of consumers' experiences with photographs
No full textPurposeThis study aims to address research calls to investigate how (visual) consumption experiences carry and convey meanings to individuals. Applying McCracken’s meaning transfer model to a photographic exhibition, the authors expand this model into the realm of aesthetic experiences to explore how the meaning of such an (visual) experience emerges and flows to (novice and expert) consumers.Design/methodology/approachThis research uses an interpretive case study of the photographic exhibition “Facing Mirrors” hosted as part of the Biennale of Contemporary Art, and draws on multiple sources of evidence, notably 50 in-depth visitor interviews, observation and archival records.FindingsThe evidence highlights the moveable nature of meaning within an aesthetic context and illustrates the critical role of semiotics and of the different ritualistic behaviors enacted by novice and expert visitors as a means of unfolding and creating the meaning of such an experience.Research limitations/implicationsThe findings provide implications in terms of (co-)creating authentic, immersive and meaningful (brand) experiences in the fields of visual consumption and customer experience management.Practical implicationsPractical implications to arts organizations are also provided in terms of curatorial practices that emphasize the material, emotional and dialogic nature of photographs as a visual art form.Originality/valueThe study provides new insights into (visual) consumption experiences by bringing the meaning transfer model together with a semiotic approach, thus illustrating different performances and sense-making activities through which (expert and novice) visitors (co-)create and appropriate the value of their aesthetic experiences
The impact of loss aversion and diminishing sensitivity on airline revenue: Price sensitivity in cabin classes
No full textWhile most businesses actively adopt a data-driven approach for revenue management decisions, understanding how air travellers perceive and behave differently to pricing strategies is essential for yielding optimal financial outcomes. This study analyses the loss aversion and diminishing sensitivity mechanisms of prospect theory in economy and business cabin classes. With rich longitudinal airfares, regression models and revenue data (15,868 observations from the top-10 aviation routes in the world) from 2014 to 2019, this study finds that lower-(higher-)than-expected airfares have a positive (negative) impact on revenue. When the effect of loss-coded and gain-coded tickets were compared, the extent to which passengers avoided losses (vs. welcomed gains) had a greater impact on revenue, supporting that loss aversion applies to the airline revenue, especially for business passengers. This study contributes to the further refinement of prospect theory by showing that the loss aversion and diminishing sensitivity mechanisms manifest differently in each cabin class
Quantitative imaging and modeling of colloidal gelation in the coagulant dipping process
No full textMany common elastomeric products, including nitrile gloves, are manufactured by coagulant dipping. This process involves the destabilization and gelation of a latex dispersion by an ionic coagulant. Despite widespread application, the physical chemistry governing coagulant dipping is poorly understood. It is unclear which properties of an electrolyte determine its efficacy as a coagulant and which phenomena control the growth of the gel. Here, a novel experimental protocol is developed to directly observe coagulant gelation by light microscopy. Gel growth is imaged and quantified for a variety of coagulants and compared to macroscopic dipping experiments mimicking the industrial process. When the coagulant is abundant, gels grow with a t1/2 time dependence, suggesting that this phenomenon is diffusion-dominated. When there is a finite amount of coagulant, gels grow to a limiting thickness. Both these situations are modeled as one-dimensional diffusion problems, reproducing the qualitative features of the experiments including which electrolytes cause rapid growth of thick gels. We propose that the gel thickness is limited by the amount of coagulant available, and the growth is, therefore, unbounded when the coagulant is abundant. The rate of the gel growth is controlled by a combination of a diffusion coefficient and the ratio of the critical coagulation concentration to the amount of coagulant present, which in many situations is set by the coagulant solubility. Other phenomena, including diffusiophoresis, may make a more minor contribution to the rate of gel growth
How does social context influence appraisal and help-seeking for potential cancer symptoms in adults aged 50 and over? A qualitative interview study
No full textObjectiveTo investigate how social context and social network activation influence appraisal and help-seeking for symptoms potentially indicative of cancer.MethodsSemi-structured telephone interview study. Community dwelling adults who had experienced at least one symptom potentially indicative of cancer within the last month were sampled from a national symptom survey.ResultsThirty-four interviews were conducted. Participants looked to peers and wider society to judge whether symptoms might be normal for their age. Involvement of others in symptom appraisal promoted an active management strategy, such as contacting a healthcare professional or trying a medication. There were practical, emotional, attitudinal, normative and moral barriers to involving others. Cancer narratives from significant others, public health campaigns and the media influenced symptom appraisal. Participants held mental representations of types of people who get cancer, for example, smokers and unfit people. This had two consequences. First, participants did not identify themselves as a candidate for cancer; impeding help-seeking. Second, social judgements about lifestyle introduced stigma.ConclusionInvolving friends/family in symptom appraisal facilitates help-seeking but barriers exist to involving others. Campaigns to promote earlier cancer diagnosis should incorporate age-appropriate narratives, address misconceptions about ‘types’ of people who get cancer and tackle stigma about lifestyle factors.<br
Membrane Attack Complex C5b-9 Promotes Renal Tubular Epithelial Cell Pyroptosis in Trichloroethylene-Sensitized Mice
No full textTrichloroethylene (TCE), a commonly used organic solvent, is known to cause trichloroethylene hypersensitivity syndrome (THS), also called occupational medicamentosa-like dermatitis due to TCE (OMDT) in China. OMDT patients presented with severe inflammatory kidney damage, and we have previously shown that the renal damage is related to the terminal complement complex C5b-9. Here, we sought to determine whether C5b-9 participated in TCE-induced immune kidney injury by promoting pyroptosis, a new form of programed cell death linked to inflammatory response, with underlying molecular mechanisms involving the NLRP3 inflammasome. A BALB/c mouse-based model of OMDT was established by dermal TCE sensitization in the presence or absence of C5b-9 inhibitor (sCD59-Cys, 25μg/mouse) and NLRP3 antagonist (MCC950, 10 mg/kg). Kidney histopathology, renal function, expression of inflammatory mediators and the pyroptosis executive protein gasdermin D (GSDMD), and the activation of pyroptosis canonical NLRP3/caspase-1 pathway were examined in the mouse model. Renal tubular damage was observed in TCE-sensitized mice. GSDMD was mainly expressed on renal tubular epithelial cells (RTECs). The caspase-1-dependent canonical pathway of pyroptosis was activated in TCE-induced renal damage. Pharmacological inhibition of C5b-9 could restrain the caspase-1-dependent canonical pathway and rescued the renal tubular damage. Taken together, our results demonstrated that complement C5b-9 plays a central role in TCE-induced immune kidney damage, and the underlying mechanisms involve NLRP3-mediated pyroptosis
Improving teamwork in maternity services: a rapid review of interventions
No full textBackgroundTeamwork is essential for providing safe, effective and women-centred maternity care and several high profile investigations have highlighted the adverse conseqences of dysfuntional teamwork. Maternity teams may need support to identify the most relevant intervention(s) for improving teamwork.ObjectiveTo identify and describe current ‘off-the-shelf’ teamwork interventions freely or commercially available to support improvements to teamworking in UK maternity services and conduct a gap analysis to identify areas for future development.DesignRapid scoping reviewMethodsA multi-component search process was used to identify teamwork interventions, comprising: (1) bibliographic database search (Medline, PsycINFO, CINAHL, MIDRS, NICE evidence research database); (2) identification of relevant policies and UK reports; and (3) expert input from key stakeholders (e.g., maternity service clinicians, managers, policymakers, and report authors). Data were extracted including the scope and content of each intervention and a gap analysis used to map interventions to the integrated team effectiveness model (ITEM) and structure level (macro, meso, micro) and results presented narratively.FindingsTen interventions were identified. Interventions were heterogeneous in their purpose and scope; six were classified as training courses, three were tools involving observational or diagnostics instruments, and one was a programme involving training and organisational re-design. Interventions were focused on teamwork in the context of obstetric emergencies (n=5), enhancement of routine care (n=4) or understanding workplace cultures (n=1). Users of interventions could vary, from whole organisations, to departments, to individual team members. All interventions focused on micro (e.g., team leadership, communication, decision-making, cohesion, and problem solving), with two also focused on meso aspects of teamwork (resources, organisational goals). Evidence for intervention effective on objective outcomes was limited.ConclusionsInterventions that address key aspects of teamworking are available, particularly for improving safety in obstetric emergency situations. Most interventions, however, are focused on micro features, ignoring the meso (organisational) and macro (systems) features that may also impact on team effectiveness. Evidence-based team improvement interventions that address these gaps are needed. Such interventions would support team ownership of quality improvement, leading to improvements in outcomes for service users, staff and organisations
Ties that Bind: The Mobilities of Thai-American Retirees
No full textThis thesis explores the diverse mobilities of Thai-American retirees in both Thailand and the United States, adopting a life-course approach to examining constellations of later-life mobilities, meanings, and experiences. It seeks to make the following original contributions: situating later-life mobilities research at the intersection of ageing, migration, mobilities and tourism; presenting a novel and comprehensive comparison of the fluid later-life mobilities of retired migrants; combining and contrasting the narratives of the retired migrants and their family members in both the countries of origin and settlement; and delving into the lesser known contexts of Thailand and the Thai transnational community. The thesis is empirically grounded on in-depth semi-structured interviews, guided by the epistemological position of constructivism and interpretivism, and accompanied by photographic accounts from the field.Results from 52 interviews conducted in California and across seven provinces in Thailand offer a number of key findings: later-life mobility is fluid, interlinking, and often overlapping, extending beyond the simple binaries of ‘staying’ or ‘returning’; meanings behind later-life mobility revolve around the ties that bind individuals to place and people, particularly their families; and continued every practices and cultural nuances with regards to religion and values contribute to retirees’ transition to the frail elderly stage of ageing and ultimately the end of life. Through compiling the findings, four themes emerge from the mobilities of Thai-American retirees: place attachments and geographies of home and belonging; social meanings and ties that bind; effects of ageing in a transnational social field; and the future trajectories of retired Thai-Americans. These demonstrate the importance of acknowledging the diversity of later-life mobilities and the specific cultural contexts they are embedded in
The utility of distributed practice in curriculum design and effective learning strategies
No full textDistributed practice, a learning strategy that can inform curriculum design, deliberately spaces out opportunities or memory storage and retrieval of taught information to develop deep, robust and long-term learning for students Dunlosky et al., 2013). Massed practice (better known to students as ‘cramming’), in contrast, involves material being studied for similar periods but without (or with little) spacing between such memory-storage-retrieval opportunities. In such cases, knowledge and skill competency are often forgotten. This translates clearly into assessment, where those who have learned in a ‘distributed curriculum’ compared to a ‘massed curriculum’ can show significant learning gains (Hattie, 2008) from the longer-lasting and deeper learning offered by spacing learning opportunities out, leading to what is referred to as the ‘distributed practice’, ‘spacing’ or ‘lag’ effect (Dunlosky et al., 2013). This effect is well documented in cognitive psychology (Latimier et al., 2020), having been demonstrated for students across ages and abilities, inside and outside of classroom environments (Agarwal, 2019; Nazari and Ebersbach, 2019), and is noted as one of the interventions that leads to the greatest learning gains for students (Hattie, 2008). Why does distributed practice work, what does it look like and where does it happen in the curriculum